The inventive subject matter relates to electrical apparatus and, more particularly, to switchgear.
In typical gas-insulated switchgear (GIS), certain components that are prone to arc generation are placed in closed structures filled with an insulating high-dielectric gas, such as sulfur hexafluoride (SF6). The insulation properties of the gas allow reduced spacing between components and thus enable relatively compact arrangement of the switchgear components. While high-voltage (e.g., 50 kV and above) switchgear is commonly gas-insulated, medium-voltage circuit breakers and other medium-voltage devices may also utilize gas insulated switching components to provide compact form factors for particular industrial and other applications.
A conventional GIS unit may include a housing having one or more gas containments compartments therein filled with insulating gas (e.g., SF6). Circuit interrupters, buses and other components may be housed in the one or more gas containment compartments. Lower voltage control circuitry and mechanisms for operating the circuit interrupters may be housed in one or more control compartments, which may not be filled with insulating gas.
In a typical application, a number of such GIS units may be arranged in a row to provide medium-voltage power distribution to other industrial devices, such as motor drives. The footprint available for such GIS units may be limited and/or expensive, and installation of the GIS units may be difficult and/or expensive due to constraints on the arrangement of feeder buses and other structures that interface with the GIS units. Accordingly, there is an ongoing need for switchgear designs that provide a smaller footprint and may be easier and less expensive to install.